package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;
    /**
     * 文件上传
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        // file是一个临时文件，需要转存到指定的位置，不然就会消失了
        log.info(file.toString());
        //获取原始文件名字
        String originalFilename = file.getOriginalFilename();
        //使用UUID重新生成文件名，防止文件名冲覅造成文件覆盖
        String fileName = UUID.randomUUID().toString();
        //获取原始文件名的后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //文件名拼接
        String fileNameSuffix = fileName+suffix;
        log.info(fileNameSuffix);
        File dir = new File(basePath);
        if (!dir.exists()){
            dir.mkdirs();
        }
        try {

            file.transferTo(new File(basePath+fileNameSuffix));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(fileNameSuffix);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        try {
            //输入流，通过输入流读取文件内容，
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));
            //通过输出流，将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");

            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }




    }

}
